Bone Marrow-Derived Dendritic Cell Cultures from RAG^-/- Mice Include IFN-γ-Producing NK Cells

Area of Science:

• Immunology
• Cell Biology

Background:

• Dendritic cells (DCs) are professional antigen-presenting cells (APCs) crucial for initiating adaptive immune responses by activating naive T cells.
• In vitro generation of DCs typically involves culturing bone marrow (BM) cells or monocytes with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4).

Purpose of the Study:

• To investigate the source of Interferon-gamma (IFN-γ) production in in vitro dendritic cell (DC) cultures stimulated with lipopolysaccharide (LPS).
• To identify cellular contaminants in bone marrow-derived DC cultures that may affect experimental outcomes.

Main Methods:

• Culture of bone marrow (BM) cells from RAG-/- and RAG-/- γc chain-/- mice in the presence of GM-CSF and IL-4.
• Stimulation of resulting cultures with lipopolysaccharide (LPS).
• Analysis of cytokine production, specifically IFN-γ.

Main Results:

• A small population of Natural Killer (NK) cells was identified in BM-derived DC cultures from RAG-/- mice, but not from RAG-/- γc chain-/- mice.
• These NK cells were the source of IFN-γ production upon LPS stimulation.
• The presence of these NK cells suggests they may contribute to early lipopolysaccharide-induced responses.

Conclusions:

• NK cells contaminating BM-derived DC cultures can produce IFN-γ, impacting LPS-stimulated immune responses.
• Researchers using BM-derived DCs must account for the presence and activity of these NK cells to accurately interpret experimental results.